256970621 has 2 divisors, whose sum is σ = 256970622. Its totient is φ = 256970620.

The previous prime is 256970603. The next prime is 256970627. The reversal of 256970621 is 126079652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 255648121 + 1322500 = 15989^2 + 1150^2 .

It is a cyclic number.

It is not a de Polignac number, because 256970621 - 2¹⁰ = 256969597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256970627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128485310 + 128485311.

It is an arithmetic number, because the mean of its divisors is an integer number (128485311).

Almost surely, 2^256970621 is an apocalyptic number.

It is an amenable number.

256970621 is a deficient number, since it is larger than the sum of its proper divisors (1).

256970621 is an equidigital number, since it uses as much as digits as its factorization.

256970621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 256970621 is about 16030.3032098585. The cubic root of 256970621 is about 635.7618903831.

The spelling of 256970621 in words is "two hundred fifty-six million, nine hundred seventy thousand, six hundred twenty-one".